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| n | a(n) |
|---|---|
| 1 | 2 |
| 2 | 14 |
| 3 | 91 |
| 4 | 600 |
| 5 | 4039 |
| 6 | 27212 |
| 7 | 183195 |
| 8 | 1233336 |
| 9 | 8303647 |
| 10 | 55905604 |
| 11 | 376392451 |
| 12 | 2534116400 |
| 13 | 17061305479 |
| 14 | 114867707132 |
| 15 | 773363450795 |
| 16 | 5206781283496 |
| 17 | 35055408051567 |
| 18 | 236015604782644 |
| 19 | 1589009194201811 |
| 20 | 10698234218839200 |
[2,14,91,600,4039,27212,183195,1233336,8303647, 55905604,376392451,2534116400,17061305479, 114867707132,773363450795,5206781283496, 35055408051567,236015604782644,1589009194201811, 10698234218839200] |